Liquid crystal display watch

ABSTRACT

A liquid crystal display watch having an electronic digital circuit having a battery driving the circuit and an astable blocking oscillator driven by the battery. The output from the oscillator is rectified and utilized for driving a liquid crystal display panel and driver circuits thereof.

United States Patent l 1 [111 3,886,724

Kamiya June 3, 1975 l l LIQUID CRYSTAL DISPLAY WATCH 3.750.383 Ei/Wgi fiakizawax. 3. 97.225 l9 t [75 Inventor: Masaaki Kamiya, Mutsudo. Japan 7 e d 73 A. z K'l :h'k' h D S 'k .h' L 1 Sslgnec il I I dis a lam H m a Primary Examiner-Edith Simmons Jackmon I Attorney. Agent, or Firm-Robert E. Burns; l l Flledi 19! Emmanuel .l. Lobato; Bruce L. Adams [21] Appl. No.: 443,185

[30] Foreign Application Priority Data [57] I ABSTRACT 1973 Japan 48-23354 A liquid crystal display watch having an electronic digital circuit having a battery driving the circuit and 2 ggl g ifi j g an astable blocking oscillator driven by the battery. 1 i h c g 73 BA 6 5 38 The output from the oscillator is rectified and utilized 8] Field 0 edrc for driving a liquid crystal display panel and driver cir- [56] References Cited cults thereof" UNITED STATES PATENTS 4 Claims, 4 Drav ving Figures 3.715.88l 2/1973 (iirurd 58/50 R ,m l3 ,Iz ,H

l2 ABlC 4 SO-ABIC DIVIDER CRYSTAL COUNTER COUNTER OSCILLATOR A A A. i a I I l r\ l L35V lo I 5 I v l r I DRIVER DRIVER BOOSTER BATTERY I"! f y PANEL PATENT EB JUE 3 75 CRYSTAL OSCILLATOR DIVIDER 60-ABIC COUNTER BATTERY 135v I2 ABIC COUNTER FIG DRIVER FIG. 3b

FIG. 30

1 LIQUID CRYSTAL DISPLAY WATCli-I BACKGROUND OF THE INVENTION This invention relates generally to a digital watch and more particularly to a watch having a liquid crystal display.

Most digital electronic watches are powered by a power supply without use of a booster circuit. Thus the power supply is drained of power more rapidly than if a booster circuit was used.

SUMMARY OF THE INVENTION It is a principal object of the present invention to provide a compact liquid crystal display watch making use of a liquid crystal display driven by a voltage produced by boosting the power supply voltage by using a booster comprising an astable blocking oscillator.

The electronic timepiece circuit according to the invention comprises an oscillator having a given or standard frequency output. The frequency is divided by a divider. The output of the divider is counted by a 60- abic or divide-by-60 counter which counts modulo 60 in series with a l2-abic or divide-by-l2 counter which counts modulo l2 A first driver circuit is connected to receive the output of the second-mentioned counter and a second driver receives the output of the firstmentioned counter. A liquid crystal display displays the outputs of the first driver as a digital output representative of time in hours and displays the output of the second driver as a digital representation oftime in minutes. A battery energizes the oscillator and the frequency divider. A voltage booster is connected to the battery for boosting the output of the battery and applying it to both of the counters and both drivers. This booster is an astable blocking oscillator.

BRIEF DESCRIPTION OF THE DRAWINGS Other objects and advantages of the timepiece circuitry in accordance with the invention will appear from the following description of an example of the invention, and the novel features will be particularly pointed out in the appended claims and drawings in which:

FIG. I is a block diagram of an embodiment ofa liquid crystal display watch according to the present invention;

FIG. 2 is a circuit diagram of a voltage booster circuit configured as an astable blocking oscillator used in the circuit illustrated in FIG. I; and

FIGS. 3(a) and 3(b) are schematic illustrations of a pot-type core construction used in the voltage booster circuit according to the invention.

DESCRIPTION OF A PREFERRED EMBODIMENT In FIG. 1 a block diagram of an embodiment of a liquid crystal display watch circuit according to the invention as illustrated. The circuitry comprises a quartz oscillator Ill generating a standard time signal or frequency corresponding to a standard time signal. A divider 12 receives the output of the oscillator and divides the output frequency thereof. The output of the divider is received by a dividc-by-oO counter 13 which counts modulo 60 in series with a di\'idc-byl 2 counter 14 which counts modulo 12. The divide-by-60 counter counts minute pulses from the divider 12 and the divide-by-l2 counter 14 counts carry pulses from the dividc-by-6O counter. The counters are connected respectively to drivers 15 and 16 for respectively driving a liquid crystal display watch panel 17.

The driver 16 will effect the display of the digital representation of the hours and the other driver 15 of the digital output of the panel corresponding to the minutes of a time display on the panel 17. The display panel is provided with liquid crystals as time display elcments.

The battery or power source 18 is connected to apply a l.3 voltage to the crystal oscillator Ill and to the divider 12. The output of the battery is boosted by a booster 19 which raises the voltage to 7 volts and applies them to both counters and drivers as illustrated in the circuit.

The booster circuit 19 is an astable blocking oscillator illustrated in FIG. 2 and comprises three parallel coils L L and L An RC circuit comprising a resistor R in parallel with a capacitor C is connected to a first coil L of the coils and in series with the base of a transistor Q having its collector connected to the coil L and its emitter connected to the negative side of the battery and to the third coil L An anode of a diode D is connected to the positive terminal of the battery through a capacitor C It is assumed that a base current flows because the base potential of the transistor Q is kept high and hence a collector current flows with terminals 1 and 2 of the coil L being positive and negative respectively. On the other hand negative and positive voltages are induced at terminals 3 and 4 of the coil L respectively thereby increasing the base current of the transistor with the result that there is an increase of the collector current.

The transistor Q is cut off as soon as the capacitor C is charged so that the polarity of the coil L reverses. That is negative and positive voltages are respectively induced at the terminals 1 and 2 thereof and at the same time also at terminals 5 and 6 of the coil L Thus a voltage summing the voltage of the battery 18 of the voltage generator across the coil L appears across the capacitor C The battery voltage of 1.35 volts is accordingly boosted to 7 volts.

A manner of constructing the coils is illustrated in FIGS. 3(a), 3(b) in which a pot-type core 31 has the coils wound thereon in parallel and made of copper wire. The coil windings are such that the terminals 3, 4 are taken from the coil L, and terminals 1, 2 from the coil L and the terminals 5, 6 from the coil L A high efficiency in boosting the voltage is obtained in the liquid crystal display watch according to the present invention because the voltage of the battery 18 is added to the voltage generated at both the terminals of the coil L What I claim and desire to secure by Letters Patent ll. An electronic timepiece circuit comprising, an oscillator having a given frequency output, a frequency divider dividing the output of said oscillator, a divideby-60 counter which counts modulo 6O counting output pulses of said frequency divider corresponding to minutes, a divide-by-l 2 counter which counts modulo 12 in series with the first-mentioned counter counting pulses corresponding to hours, a first driver connected to receive the output of the second-mentioned counter, a second driver connected to receive the output of the first-mentioned counter, a display panel displaying the output of said first driver as a digital output representation of time in hours, and displaying the output of the second driver as a digital output representation of time in minutes, a battery energizing said oscillator and said frequency divider, and a voltage booster comprising an astable blocking oscillator connected to said battery for boosting the output of said battery and applying it to both of said counters and both of said drivers.

2. An electronic timepiece circuit according to claim 1, in which said astable blocking oscillator comprises a rectifier element rectifying the output thereof.

3. An electronic timepiece circuit according to claim 2, in which said astable blocking oscillator comprises said battery, three coils in parallel across said battery,

coil. 

1. An electronic timepiece circuit comprising, an oscillator having a given frequency output, a frequency divider dividing the output of said oscillator, a divide-by-60 counter which counts modulo 60 counting output pulses of said frequency divider corresponding to minutes, a divide-by-12 counter which counts modulo 12 in series with the first-mentioned counter counting pulses corresponding to hours, a first driver connected to receive the output of the second-mentioned counter, a second driver connected to receive the output of the first-mentioned counter, a display panel displaying the output of said first driver as a digital output representation of time in hours, and displaying the output of the second driver as a digital output representation of time in minutes, a battery energizing said oscillator and said frequency divider, and a voltage booster comprising an astable blocking oscillator connected to said battery for boosting the output of said battery and applying it to both of said counters and both of said drivers.
 1. An electronic timepiece circuit comprising, an oscillator having a given frequency output, a frequency divider dividing the output of said oscillator, a divide-by-60 counter which counts modulo 60 counting output pulses of said frequency divider corresponding to minutes, a divide-by-12 counter which counts modulo 12 in series with the first-mentioned counter counting pulses corresponding to hours, a first driver connected to receive the output of the second-mentioned counter, a second driver connected to receive the output of the first-mentioned counter, a display panel displaying the output of said first driver as a digital output representation of time in hours, and displaying the output of the second driver as a digital output representation of time in minutes, a battery energizing said oscillator and said frequency divider, and a voltage booster comprising an astable blocking oscillator connected to said battery for boosting the output of said battery and applying it to both of said counters and both of said drivers.
 2. An electronic timepiece circuit according to claim 1, in which said astable blocking oscillator comprises a rectifier element rectifying the output thereof.
 3. An electronic timepiece circuit according to claim 2, in which said astable blocking oscillator comprises said battery, three coils in parallel across said battery, and RC current in series with one of said coils, a transistor in series with said RC circuit across said battery, means connecting said one coil to the base of said transistor, a second of said coils connected to the collector of said transistor, means connecting the emitter of said transistor to a negative side of said battery and to the third coil. 